The best greenhouse shade cloth, by percentage and crop
The short answer
Use 30 to 50 percent shade cloth for seedlings and leafy greens, 40 to 50 percent for fruiting vegetables such as tomatoes and peppers, and 60 to 75 percent for orchids and shade ornamentals. The Bellebill 50 percent cloth at roughly $25 is the right default for a mixed vegetable house. Fit it on the outside of the glazing, since cloth inside has already let the heat in.
Vegetables
40 to 50 percent
Seedlings
30 to 50 percent
Orchids
60 to 75 percent
Fit it
Outside the glazing
Researched from published specifications and verified owner reviews · Updated 2026-08-16
Shade cloth is the cheapest cooling in a greenhouse and the most misunderstood. It has no running cost, no moving parts and no water use, and it removes solar energy before that energy enters the structure, which no fan or cooler can do. The single decision that matters is the percentage, and the second is where you hang it.
For a mixed vegetable and flower house the default is 50 percent shade cloth at around $25, which is the correct specification for fruiting crops rather than a compromise between competing needs.
50 percent knitted shade cloth, which is the right default for a house growing tomatoes, peppers, cucumbers and mixed flowers. The reasoning is not that half the light is a reasonable compromise, it is that photosynthesis in these crops saturates well below full summer sun, so the light removed above that point was contributing heat rather than growth. Knitted rather than woven matters practically: knitted cloth does not fray or unravel when cut, so it can be sized to a specific roof without hemming.
Shade percentage is the proportion of light the fabric blocks. The correct figure is set by the crop and, secondarily, by your latitude and season. Getting it wrong in either direction is costly: too little and the house overheats and fruiting crops abort flowers, too much and growth slows for want of light.
Figure 1. Shade percentage by crop and situation·11 rows
Figure 1. Shade percentage by crop and situation
Crop or situation
Shade percentage
Reasoning
Seed germination trays
50 to 60%
Protects the surface from drying before roots establish
Seedlings and transplants
30 to 50%
Enough light to prevent stretching, enough shade to prevent scorch
Lettuce and leafy greens
40 to 50%
Reduces bolting and tipburn in heat, which are the main summer losses
Tomatoes and peppers
40 to 50%
Photosynthesis saturates below full sun; above 90 F flowers abort
Cucumbers and squash
30 to 40%
High light demand, but leaves scorch in still greenhouse air
Strawberries
30 to 40%
Fruit quality suffers in deep shade; heat stress reduces set
Herbs, most kinds
30 to 40%
Essential oil content is higher at higher light
Geraniums and bedding flowers
30 to 50%
Flower colour and habit both suffer in heavy shade
Orchids, most kinds
60 to 75%
Adapted to filtered canopy light; direct sun burns foliage
Ferns and deep shade plants
70 to 80%
Native to forest floor light levels
Overwintering, any crop
0%
Winter light is the limiting factor; remove shade entirely
Researched figures for temperate summer conditions. In high-sun regions and at low latitudes, move up one band. In northern regions and in spring or fall, move down. Shade requirements are seasonal and cloth should come off entirely for winter, when light rather than heat is the constraint.
The point most often missed is the last row. Shade cloth left on through winter is a real yield penalty, because in a northern midwinter the daily light integral inside a greenhouse can already fall below what lettuce needs. Shade is a summer tool, and taking it off is as important as putting it on. The light targets are in the DLI targets chart, and the percentages tabulated in the shade cloth chart.
The three tiers
Shade cloth in three tiers
3 tiers · priced at the time of writing
Beginner
A hobby greenhouse growing a mixture of vegetables and flowers.
50 percent knitted cloth is the single most useful specification in the category, because it is genuinely correct for fruiting vegetables rather than being a middle setting. Knitted construction means it can be cut to fit a specific roof without fraying, and it is light enough to fit and remove seasonally by one person, which matters because removing it in fall is as important as fitting it in spring.
The trade-off:
One percentage cannot suit both a tomato house and an orchid collection. If you grow shade plants, this is not enough shade for them, and if you overwinter it must come off entirely.
Buying one correctly sized piece rather than joining several is worth doing, because every join is a place where cloth flaps, abrades and eventually tears. A single panel with reinforced edges and grommets can be tensioned properly, and a properly tensioned cloth lasts far longer than a loose one because most shade cloth failure is abrasion from movement rather than UV degradation.
The trade-off:
A large single piece is awkward for one person to fit on a roof, and it commits you to one shade percentage across the entire house rather than allowing different zones.
70 percent is the correct band for plants adapted to filtered canopy light, where direct sun burns foliage regardless of temperature. It is also the right specification for a propagation zone within a larger house, where cuttings and germinating trays need protection from surface drying more than they need maximum light. Running two shade percentages in different parts of a house is a genuine refinement.
The trade-off:
Far too much shade for fruiting vegetables, which will grow leggy and set poorly beneath it. This is a specialist specification rather than a general upgrade.
This is the detail that determines whether shade cloth cools effectively, and it is got wrong constantly.
Cloth fitted outside the glazing intercepts solar radiation before it enters the structure. The energy absorbed by the fabric is dissipated to the outside air, and it never becomes heat inside the greenhouse.
Cloth fitted inside the glazing intercepts the same radiation after it has already passed through. The fabric absorbs it, warms, and re-radiates into the same air volume you are trying to cool. Interior cloth reduces light on the plants and provides some benefit by keeping direct sun off foliage, but as a cooling measure it is worth a small fraction of the same cloth fitted outside.
The gap matters too. Cloth held a few inches clear of the glazing allows air to move between the two, carrying heat away. Cloth laid directly on the glazing conducts heat straight into the panel. Standoffs or a simple frame of battens make a measurable difference for almost no cost.
Field tip
Tension it, because movement is what destroys it
Most shade cloth fails from abrasion rather than sunlight. A loose cloth flaps against the ridge and the frame edges thousands of times a season, and it wears through at exactly those contact points. Tension it drum-tight with the reinforced edge and grommets, use enough fixing points that no span can billow, and pad any sharp frame edge it bears against. A well-tensioned cloth will outlast a loose one of better quality by years.
Knitted versus woven
Two constructions dominate and the difference is practical rather than optical.
Knitted cloth is made from interlocked loops of polyethylene tape. It does not fray or unravel when cut, so it can be sized to a specific roof with scissors and no hemming. It stretches slightly under tension, which lets it conform to a curved or irregular roof, and it is lighter to handle. It is the right choice for almost all hobby use.
Woven cloth is made on a loom and unravels at a cut edge unless hemmed or heat-sealed. It is dimensionally stable, does not stretch, and generally has a longer service life under constant tension. It suits fixed installations sized exactly to a structure, and it is what most commercial shade houses use.
Colour matters less than the marketing suggests. Black cloth absorbs and dissipates heat outside the structure and gives a slightly cooler house; white or aluminized cloth reflects more and transmits more diffuse light, which some growers prefer for even canopy illumination. The difference is real but small next to the choice of percentage and the decision to fit outside rather than inside.
Shade cloth versus whitewash
The traditional alternative is a shading paint or whitewash applied to the glazing, which is still widely used and has genuine advantages worth understanding.
Whitewash costs less per square foot, needs no fixings, and cannot flap or tear. It also gives completely even diffuse shading with no stripes or hot spots. Its disadvantages are that it is a one-way decision until you wash it off, it cannot be removed for a cool cloudy week, and it must be reapplied each season.
Shade cloth is removable, adjustable and reusable across many seasons. On a house where the crop changes through the year, that flexibility is worth more than the cost difference. The full comparison is in shade cloth versus whitewash.
How we chose
We did not measure light transmission through these fabrics, and any site claiming photometric verification of four shade cloths is telling you a story. We compared stated shade percentage, construction type, UV stabilization claims, edge reinforcement and grommet spacing, available sizes, and verified owner reviews weighted toward multi-season durability.
One caution on stated percentages generally: they are nominal and manufacturing tolerance in this category is wide. A cloth sold as 50 percent may measure anywhere from roughly 45 to 55 in practice, and the figure is measured on the fabric rather than on the installation, where overlap at joins and the shading of the frame itself add several points. For horticultural purposes this is fine, since crop tolerance bands are broad, but it is a reason not to agonize between a 40 and a 50 percent cloth.
We weighted edge construction heavily because it predicts service life better than fabric quality does. Cloth fails at its fixing points, so reinforced hems with closely spaced brass or nickel grommets outlast cloth with sparse grommets punched straight through the fabric, regardless of the material specification.
What goes with it
The rest of the summer system
Shade is the first cooling stage. These are the others, plus the measurement that tells you whether the percentage you chose is right for your crop.
A PAR meter tells you what light actually reaches the canopy under the cloth, which is the number that decides whether you have shaded correctly or over-shaded.
+- What percentage shade cloth do I need for a greenhouse?
40 to 50 percent for a mixed vegetable house growing tomatoes, peppers, cucumbers and flowers, which suits most hobby growers. 30 to 50 percent for seedlings and leafy greens, 60 to 75 percent for orchids and shade ornamentals, and 70 to 80 percent for ferns. Move up one band in high-sun regions and low latitudes, and remove shade entirely for winter, when light rather than heat is the limiting factor.
+- Should shade cloth go inside or outside the greenhouse?
Outside, and it makes a substantial difference. Cloth outside intercepts solar radiation before it enters the structure, and the heat the fabric absorbs is dissipated to the outside air. Cloth inside absorbs radiation that has already entered and re-radiates it into the air you are trying to cool. Hold it a few inches clear of the glazing so air can move between the two.
+- Does shade cloth reduce greenhouse yield?
At the correct percentage, barely at all for fruiting vegetables, because photosynthesis saturates well below full summer sun and the light removed above that point was contributing heat rather than growth. Heat stress above 90 degrees F causes flower abortion in tomatoes and peppers, so shade frequently increases yield. Leaving shade on through winter is a genuine yield penalty, which is why it should be seasonal.
+- When should I put shade cloth on a greenhouse?
When daytime temperatures begin regularly exceeding the crop optimum, which in most temperate regions is from late spring through early fall. Take it off as soon as the heat stress period ends, because winter light is frequently the limiting factor on growth and shading a greenhouse in low light costs yield directly. Treat fitting and removing as two equally important seasonal jobs.
+- Is knitted or woven shade cloth better?
Knitted for almost all hobby use, because it does not fray or unravel when cut, so it can be sized to a specific roof with scissors and no hemming. It also stretches slightly, which helps it conform to curved roofs. Woven cloth is dimensionally stable and longer lasting under constant tension, which suits fixed commercial installations sized exactly to a structure.
+- How long does greenhouse shade cloth last?
Typically five to ten years for UV-stabilized cloth, but installation quality predicts service life better than material quality does. Most failure is abrasion from movement rather than UV degradation: a loose cloth flaps against the ridge and frame edges thousands of times a season and wears through at those points. Tension it drum-tight, use enough fixings that no span can billow, and pad sharp frame edges.
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